: Aim 1 will determine the optimal combination of supplemental AOE required to protect cells from hyperoxia. This will be done using a pulmonary epithelial cell culture system exposed to hyperoxia. Aim 2 is to improve the distribution and uptake of AOE in the lung. Stabilized suspensions will be tested in cell culture and in mice exposed to hyperoxia for their effects on cell viability, virus infectivity, multiple gene delivery and expression, and degree of injury. Aim 3 will use viral constructs containing AOE genes under the control of the human SP-B promoter (to target Type II or Clara cells) or the CMV promoter. Aim 4 is to compare the effects of PFC-protein or adenoviral-associated AOE suspensions on normal or injured, preterm or term lamb lungs, using assays for levels and duration of transgene expression.